Light ring indicating apparatus



J. S. STEVENSON LICK- '1 RING INDICATING APPARATUS March 8, 1960 Filed Sept. 29, 1955 2 Sheets-Sheet 1 INVENTOR. JOHN SHAW STEVENSON BY; y i 4 FIG.

ATTORNEY.

March 8, 1960 J. 5.. STEVENSON LIGHT RING INDICATING APPARATUS 2 Sheets-Sheet 2 Filed Sept. 29, 1955 FIG.3

INVENTOR. JOHN SHAW STEVENSON ATTORNEY:

United States Patent O LIGHT RING lNDICATlNG APPARATUS John Shaw Stevenson, Philadelphia, Pa., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, I Minn., a corporation of Delaware Application September 29, 1955, Serial No. 537,525

13 Claims. (Cl. 340-324) A general object of the present invention is to provide a simple and effective visual indicator which can be accurately read by an observer looking at the indicator from any number of difierent and unrelated positions.

The indicator which I have devised for the practice of the present invention, comprises a translucent shell of the general form of a paraboloid of revolution. It further includes a means for casting a circular illuminating light ring, which may or may not include a shadow casting ring on the curved portion of the shell which extends circularly about the longitudinal axis of the shell. The light for such rings may be developed by a suitable source of light within or at the outer side of the shell. The indicator ordinarily includes adjustment provisions for moving the aforementioned illuminating means axially toward and away from the base of the paraboloid in accordance with a variable input applied to a casing retaining such an illuminatingmeans.

Thus, another object of the present invention is to provide an illuminating means which will not only cast an indicating light ring on the curved surface of a shell but will also enable the diameter of the light ring cast on that shell to be gradually enlarged as when one input is applied to the light ring casing or to be gradually diminished as an opposite input is applied to the light ring.

Still another object of the present invention is to provide an easy and rapid means of indicating whether a variable is below, at, or above a preset value by observing whether a light ring cast on a translucent shell is a selected color such as green, white, or red.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages, and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described preferred embodiments of the invention.

In the drawings:

Fig. l is a section intersecting the axis of a hollow, translucent paraboloid showing how its hollow base portion is inserted in a circular aperture of an instrument panel for mounting thereon, and an annular member surrounding and movable longitudinally of the paraboloid;

Fig. 2 is a sectional view taken at right angles to Fig. 1, and including elements not shown in Fig. 1;

Fig. 2A shows a view looking down at the shell shown in Figs. 1 and 2 from a position above and to the right of the longitudinal axis of the shell;

Fig. 3 illustrates a modification of the apparatus shown in Fig. l which is coaxial with the shell and extends through an aperture in the end portion of the shell, and includes an adjustable light source within an adjustable tube; V

Fig. 4 is a modified arrangement including a tube coaxial with and extending through the end wall of the shell;

Fig. 5 illustrates a modified form of the apparatus shown in Fig. 3 which has the shell protruding outwardly from the right side of an instrument panel; and

Fig. 6 is a front elevation view of the shell shown in Fig. 5.

The embodiment of the invention shown by way of example in Fig. 1, comprises a hollow translucent body or shell a in the form of a hollow paraboloid with a circular shell section b anchored in the circular aperture c of an instrument panel d. The shell a may advantageously be formed of a translucent plastic material such as polyethylene, a ground or frosted glass, or any other material which will give the same light and shadow ring transferring qualities as are inherent in a thin eggshell type material. An annular member e, ordinarily formed of metal, surrounds and is coaxial with the shell a, and has curved inwardly extending side flanges f, fa. As shown, the inner edges of said flanges diverge in opposite directions from a plane transverse to the axis of the shell a. A light source g, shown as a continuous, internally illuminated, glass tube, is surrounded and supported by the member e, and is spaced between the flanges f, fa. Circumferentially surrounding the light source g there is shown an opaque ring h which has its outer peripheral portion fixedly attached to the center of the inner ring surface of light g by means of a suitable clip or by fusing these two parts together. The opaque material used for this ring may be any metallic material, such as Invar, of a small diameter having a low coeflicient of expansion. The light source g and ring h cooperate to form a relatively narrow circular light ring i at opposite sides of an annular shadow ring 111.

The outermost circumferential portion of annular member e may be supported in any suitable and convenient manner. As shown in Fig. 2, this outermost portion of annular member 2 is shown supported on the parallel guide bars 1' and fa by means of suitable sliding members jb and jc. As shown, the two guide bars and fa are attached to the panel d and extend perpendicularly away from said panel at opposite sides of the shell a. The ends of the guide bars and fa remote from the panel d are connected by a supporting ring k. As the light rings i and the opaque ring h are moved by an input motion, representative of the magnitude of a variable to be measured, toward and away from the panel d, the diameter of the portion of the shell a intersected by the shadow ia of ring h increases and decreases.

Provisions are advantageously made to show the extent to which the opaque ring it in the annular member e is displaced from the panel a. Thus, as shown in Fig. 2A, the magnitude to which the ring h has been displaced from the panel d, is indicated by the circular narrow ring shadow ia that it casts on an area of the inner shell portion between the numbers 15 and 20. The numeral 20, by way of an example, is shown at two locations on the inner side of the shell a. One of the numbers marked 20 is in solid line form and is visible to an observer whose line of sight is at a position above and to the right of the longitudinal axis of the shell a. From this vantage point, three other numbers on a, one of which is marked 20 in dotted line form, will not be visible to an observer in this position. This group of four nur'nerals is placed on the inner portion of the plastic shell a by etching the shell with an etching fluid e.g. hydrofluoric acid or through the use of a permanent ink. In either event, a set of four numbers for each numeral 15, 20, etc., is inscribed on the shell at approximately forty-fivedegree angles on and with respect to a hori- 3 zontal center line passing through the longitudinal axis of the shell. If this is done, anaccurate instrument read ing may be made by an observer from any angle that is below, above, to the right or left of the instrument. This is possible since the observer when in any of the above mentioned positions will be able to observe at least one of any one set of these four numerals through which the lit up ring shadow ia passes. As shown, in Fig. 2A the shadow ring passes through a shell a area which lies between the four numerals on the ring marked 20 and four numbers, all of which are not shown, on the ring marked 15. The position of this ring shadow thus indicates that it has been displaced a greater distance from the panel d than if the shadow ring were passing e.g. through the four members marked 20. A complete set of such numbers ranging from -100 representing different distances from the panel d may be marked in a similar manner on the shell a when it is desirable to indicate the magnitude of the variable being transmitted to the annular member e in the form of a longitudinal motion.-

It can thus be seen that the form of the invention disclosed in Figs. 1, 2 and 2A provides a light ring source g for lighting up a circumferential internal portion of a shell a.

These Figs. 1, Z and 2A also disclose how an opaque ring it of small cross sectional area may be aflixed to the central portion of such a light ring source g so that the ring will cause a shadow in to be cast on the aforementioned circumferentially lit up portion of the shell a..

Any conventional means such as the two pinion-rack drives E E and a similar drive E shown in Fig. 2A may be used to move the annular member e and its sliding members jb, jc fixedly attached thereto along the bars j, ja, as shown in Fig. 2, toward the front or rear portion of the shell 0 depending on whether a variable input signal received by such a drive is increasing or decreasing. Many other types of drives may be used in lieu of the pinion-rack drive to move the ring along the bars j, in shown in'Fig. 2. One such other drive might well be a link actuated by a pneumatic receiving bellows, not shown, which in turn is itself actuated in accordance with the magnitude of a variable pressure.

As the aforementioned guide bar movement takes place a shadow of the opaque ring it will be moved circumferentially along the shell a to either a position that is closer to or further away from the instrument panel d depending on whether the magnitude of the variable is increasing or decreasing.

Fig. 3 diagrammatically illustrates a modification of the apparatus shown in Figs. 1 and 2, in which the shell a of Figs. 1 and 2 is replaced by a shell aa. The base of the shell an is shown attached to a panel d in the same manner as that shown in Fig. l. The shell aa of Fig. 3 differs from the shell a of Figs. 1 and 2 in having an aperture ab in its end remote from the associated panel a. A tubular element l which surrounds; and is shown as coaxial with the axis of the shell aa, extends through the aperture ab and has portions normally extending away from the aperture ab in each direction. The portion of the tubular element 1 extending through the aperture ab and away from the panel d, is formed with a row of gear teeth m extending longitudinally of the element 1. The tubular element l and its gear teeth In form a rack bar n with its teeth in mesh with a spur gear 0 supported by a shaft p. The latter is rotatable about a fixed axis by a knob g. The longitudinal adjustment of the tubular element 1, effected by rotating the shaft p, is a set-point adjustment.

In one desirable form, the tubular element 1 of Fif. 3 includes a green glass tube section 1', a red glass tube section 5 and a short intermediate tubular glass section t between the two colored glasses through which white light may be transmitted. The section t is adapted to pass white light outward through a circumferential slit in the tube 1 or the portion of the ring of glass at this section t may be made of a transparent material that will permit the transmission of white light therethrough as shown. The sections r, s, and 2 may be connected in any suitable manner. For example, the tubesections r and 5 may be joined by welding one of their ends to the opposite ends of a short intermediate annular clear glass section. If it is desired to make the tube r, t, and s of one piece construction radial apertures may be punched into the central tube section t through which white light may be transmitted. As shown, light is transmitted away from the periphery of a circular light source it Within the tubular element 1. Two spaced apart discs no and uh fixedly attached to the conduit v in any conventional manner e.g. by welding are shown at the opposite sides of the light source proper. This circular light source'u is shown fixedly attached to a hollow conduit v by means of suitable clips Me, Ltd. The hollow conduit v is purposely made hollow so as to provide a means through which the electrical connections as, uf from the light source may pass to a current source. The external surface of this conduit v is slidably mounted in a suitable bearing va which is in turn fixedly attached to the tubular element 1. Although not shown the current source could be located at some convenient position adjacent the left end of the hollow conduit v. The outermost peripheral surfaces of these discs ua, 14b are so positioned with respect to one another that they jointly form a continuous peripheral gap through which a narrow circular stream of light may be emitted. The light source a may thus be axially adjusted relative to the tubular element 1 so as to pass this narrow circular stream of light through the transparent section t the green colored section r or through the red sections s. To accomplish this the light it and its associated discs at: and ub is axially adjusted by the longitudinal movement of the rod v which has rack teeth w movably engaged by the motion of the teeth of a gear x. This gear x is mounted external of the tubular element 1 for rotation on a shaft xa journaled in a fixedly mounted support xb.

Ordinarily the gear wheel x will be rotated in automatic response to variations in a control condition and thereby move the light source it toward or away from the vertical plane of the panel d. The effect of the longitudinal adjustment of the light source it is thus to move the source it into and out of the position in which a white light is transmitted through the annular transparent section 2. The time it will take to move this light source u into and out of the aforementioned position is dependent upon the relative positions of the light source it and the white light transmitting section t of the tube I.

In ordinary practice, the shaft xa is rotated automatically in accordance with the magnitude of a control condition e.g. the temperature of a furnace not shown. When such a temperature is below the desired set point value from the light source it a narrow circular stream of light will be applied through the green colored portion r of the central tube 1', s, t. This will cause a green light ring to be cast on the inner translucent wall of the shell aa. As the temperature increases the shaft .m' and gear x fixedly attached thereto will be rotated in a clockwise direction. This gear movement will cause the conduit v and light source 1: attached thereto to be moved to the right toward the position shown in Pig. 3. When the light source u reaches the selected set point or Fig. 3 position the previously mentioned green colored light ring that was being cast on the inner wall when the temperature was below the set point will now be changed. to a white light ring. When this white light ring appears the temperature of the furnace will be at some desired preselected set point value. Should the temperature of the furnace rise above such a set point value the white light ring being cast on the inner wall will be turned into t a red light ring asithe light 11 is moved further toward the frontof the panel a. i

It can thus be seen that the present invention as disclosedin Fig. 3 provides an easy and rapid way of determining'whether a variable such asthe temperature of a furnace is below, at or above a predetermined setpoint value by merely observing whether'the light ring is green,

white, or red.

1 In the modification: shown inFig; 4, a tubular element laextends axially through an aperture in-the shell aa, which is similar to the shell aa of Fig. 3. The element la is a translucent tubular body advantageously formed of Lucite having a highly polished outer diametrical surface, and is'axially adjustable by any suitable means e.g. the type of gear and rack means as shown in Fig. 3. The inside diametral surface of the main left hand portion lb of the inner wall of the tube la is recessed and rough ened, but the inside surface of the right end portion lc adjacent the panel d; is highly polished. In consequence, the tubular body la is adapted to pass a broad band of white light from a light source ld through its wall portion lc onto the insideof the shell an as indicated by the two dotted lines adjacent the right end of the tube la. The roughened portion lb of tube la that extends back to a fixedly mounted opaque plate If will cause the light passing through same to cast ashadow as indicated on the shell aa that circumvents this roughened portion lb. If the lightbulb is not of the silvered top type an opaque plate 'lemay be fixedly attached to the right end of the tube la to prevent the rays of light from being transmitted through the right end of the tube.

It can thus be seen that the present invention as disclosed in Fig. 4 provides a means of moving a light and shadow ring along the inside surface of a hollow shell so that the value of a variable may be readily obtained by observing the shell scale marking through which the left end of the light ring is passed.

' In this regard it should be noted that although no scale marking has been indicated for some of the figures, e.g. Fig. 4, it is intended that such scale markings be made in the same manner as that set forth under the description of Fig. 2A.'

. The modification shown in Fig. 5 shows 'a preferred form of the present invention in which the shell ab protrudes outwardly from or to the right of the panel rather than being compressed into the panel as shown in Figs. 1, 2, 2A, 3, and 4. The operation of the lightprojecting means along the axisof the shell is substantially the same as that already described under the description of Fig. 3. The only difference being that the green, white, or red light rings projected through to the outer surface of the shell ab are observed rather than the light rings which are projected on an inner wall as in Fig. 3.

Fig. 6, which is a front elevation of the shell ab shown in Fig. 5, shows how various numerals such as and may be printed on four circumferentially spaced portions "of the outer surface of the shell.

, When the light from the light source shown in Fig. 5 has been moved to a location in which it projects a light ring through e.g. all of the members marked 15 an observer may clearly read such a number regardless of whether his line of sight is from a position below, above, to the right of or to the left of the longitudinal axis of the shell. This is made possible since in any one of these positions an observer will be able to read at least one of the: shell scale markings shown.

As will be apparent to those skilled in the art, each of 'the diiferent forms of the invention illustrated and described herein by way of example, is adapted to show one or more light bands which can be seen from a plurality of view points. While some of said light bands may be seen only from the inner side, or only from the outer side of the shell, with other forms of the invention, annular light bands may be observed by inspection of either the inner side or the outer side of said shell. In each of I;have illustrated and described the best forms of embodiment of my invention now known to me, it will be 1 apparent to those skilled in the art that changes maybe made in the forms of 'the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain featuresof my invention may be used to advantagewithout a corresponding use of other features.

- Having now described my invention, what I claim as new and desire to secure by Letters Patent is: 15

[1 An indicatingapparatus, comprising a translucent indicating shell extending circularly about an axis and including a non linear tapered portion extending between spaced apart circular sections of said shell, a tubular body within and. coaxial with said shell, means for adjusting said body in the direction of said axis, and means within said tube for transmitting through said tube to the inner side of said shell a light ring of fixed width extending radially away from a circular portion of said tubular body.

)2 An indicator comprising a translucent indicating shell. of parabolical configuration, a light transmitting means of afixed width illuminating a circular portion of said shell, and means for moving the said light means coaxial with the longitudinal axis of said shell in accordance with a variable mechanical input movement applied thereto so as to change the diametral dimension of said illuminating'circular'portion appearing on said shell.

3. The combination ,of a translucent indicating, shell extending circularly about an axis and including a nonlinear tapered portion extending between spaced apart circular sections of said shell, a hollow cylindrical tube within. and coaxial with said shell, said tube having a first transparent cylindrical band portion centrally positioned between the ends of .the tube, a second colored cylindrical band portion adjacent and on one side of said first portion and a third cylindrical band portion adjacent and on the remaining side of said first portion of a difierent color than said second mentioned portion, means for moving said tube along said axis of said shell to align said first portion with a variable set point marking on said indicating shell, a cylindrical white light transmitting means within said tube, a mechanical means for moving said light, transmitting means along the center portion of said tube in accordance with the magnitude of a variable received by said mechanical means, said light transmitting means acting to transmit a light ring of gradually increasing diameter through said first colored band onto said shell as said variable approaches a preselected set point value, a white light ring through said first band onto said shell when said variable is at said set point and a light ring of gradually increasing diameter through said second band ontosaid shell as said variable continues to go beyond said set point value.

4. A light ring indicator for indicating the magnitude of a variable, comprising a translucent indicating shell of parabolic configuration, a hollow cylindrical tube having a highly polished outer surface, said inner surface of said cylindrical tube having a band portion of one diameter which has a highly polished surface and having a second band portion of a different diameter which has a dull surface, a means actuated by the magnitude of a variable for moving an illuminating light source along the central portion of said tube said light source acting to transmit a light ring of varying diameter on and through said two surfaces, onto said shell as said magnitude of said variable is changed.

5. An indicating apparatus, comprising a translucent indicating shell extending circularly about an axis and including a non-linear tapered portion extending between spaced apart circular shell sections, a light source juxta- "positioned with respect to said shell and having a light restricting means thereon to cast a circular ring of light of afixed'w'idth on said shell and meansoperable to move said light source along said axis of said shell to enable said ring of light being cast thereon to be aligned with a first set of indicating markings on one of said circular shell sections, a second set of indicating markings on said non-linear tapered portion or a third'set of indicating markings on said other of said circular shell sections.

6. An indicating apparatus, comprising a translucent indicating shell that extends circularly about an axis having a non-linear tapered portion which extends 'between spaced apart circular shell sections, an adjustable masked light transmitting means operably positioned within said shell to transmit a ring of light of fixed width and of varying diameter on dilferent circumferential portions of said shell as said masked light is adjusted along said axis and wherein the location of said ring of light on said circumferential portions forms an indicating means on said indicating shell whose position can accurately be identified by inspectionof said shell from angles variably displaced from said axis of said shell.

7. An indicating apparatus, comprising a translucent indicating shell that extends circularly about an axis :having a curved portion that is connected at one end'to a first circular section and connected at its other end to another circular section of said shell, means for illuminating a circular portion or" any one of said three portions of said shell by means of a circular light source coaxial with said shell, a casing having a circumferential light ejecting slit therein surrounding said light source to restrict said illuminated portion to a vfixed width and means operably to move said light source along said axis of said shell in accordance with the magnitude of an input force applied thereto.

8. An indicating apparatus, comprising a translucent indicating shell extending circularly about an axis and including a non-linear tapered portion extending between spaced apart circular sections of said shell, a light source coaxial with said shell and circumferentially spaced from one side of said shell to illuminate a circular portion thereof which illumination is of a fixed width, an opaque ring coaxial with said shell and in a plane passing through a center portion of said light source that is coaxial with said shell to provide a ring shadow indication on said indicating shell when said light source and said opaque ring are moved in a longitudinal direction along the axis of said shell.

9. An indicating apparatus, comprising a translucent indicating shell extending circularly about an axis and including a non-linear tapered portion extending between spaced apart circular section of said shell, a circular light source coaxial with said shell, an opaque circular body concentric with and at the inner side of said circular light source, an annular hood surrounding said light source having inwardly extending flanges alongside and spaced away from said light source to provide a fixed band of light on said shell and an opaque ring adjacent and surrounded by said light source to provide a ring shadow indication on said indicating shell when said light source and said opaque circular body are moved in a longitudinal direction along said axis of said shell.

10. An indicating apparatus, comprising a translucent indicating shell extending circularly about an axis and including a non-linear tapered portion extending between spaced apart circular shell sections, a light transmitting means to cast a circular ray of light of a fixed width onto a portion of said shell whereby the position of said circular ray on said shell can be accurately determined by visual inspection of said shell from viewpoints variably displaced from the axis of said shell and means operably connected to move said light transmitting means coaxial with the longitudinal axis of thenon-linear tapered portion of said shell in accordance with the magnitude 'of a variable mechanical input signal to change the diameter of said light ray appearing on said non-linear tapered portion.

1-1. A light ring indicator for indicating the magnitude of a varying input signal, comprising an indicating scale of a hollow parabolic shaped configuration, a light ring projecting means within the hollow portion of said scale operably connected to transmit a first colored light ring of a fixed'width and of a diminishing diametral size to said scale as the magnitude of an input signal being applied to said light ring is increased and said light ring projecting means is moved along one portion of said scale to transmit a white light ring of a fixed diameter and of said fixed width to said scale when said input signal reaches a' pre-determined value and to transmit a second colored light of a diminishing diameter and of said fixed width to said scale as the magnitude of said input signal increases beyond said pre-determined value.

12. An indicating apparatus, comprising a translucent indicating shell extending circularly about an axis and including a non-linear tapered portion extending between spaced apart circular shell sections, a light source juxtapositioned with respect to said shell and having a light restricting means thereon to cast a circular ring of light of a fixed width on said shell and meansoperable tomove said light source along said axis of saidshell to enable said ring of light being cast thereon to be aligned with a first set of indicating markings on one of said circular shell sections, a second set of indicating markings on said non-linear tapered portion or a third set of indicating markings on said other of said circular shell sections and wherein the location of at least one of said sets of numbers on each of said shell sections and said tapered portion can always be accurately determined by visual inspection of said shell from a viewpoint that is variably displaced in a downward-upward left or right direction from said axis.

13. A light ring indicator for indicating the magnitude of a variable, comprising an indicating scale of a hollow parabolic shaped configuration, a light ring projecting means to provide a fixed width of light positioned within the hollow portion of said scale operably connected to transmit a first colored light ringof a diminishing diametral size to said scale as the magnitude of a variable being appliedto said light ring is, increased and said light ring projecting means is moved along one portion of said surface, to transmit a white light ring of a fixed diameter to said scale when said variable reaches a predetermined value and being further operably connected to transmit a second colored light of a diminishing diameter as the magnitude of said variable exceeds said .pre' determined value.

References Cited in the file of this patent UNITED STATES PATENTS 1,461,418 Harrington July 10,1923 1,942,343 Melik-Minass'iantz Jan. 2, '1934 01,405 Noel ,Mar. 21, 1950 6,533 Cannon Jan. 2, 1951 2, 21 Le Goff Oct. 126, 1954 2,761,056 Lazo Aug. 28, 1956 0,800 Lauler Feb. 5, 71957 was. QMMM 

